A zinc mineral inhibitor, a flotation separation method for copper-zinc sulfide minerals and its application

Abstract

The present invention relates to the field of mineral processing technology, and more specifically, to a zinc mineral depressant and a flotation separation method for copper-zinc sulfide minerals and their application. The zinc mineral depressant comprises modified tamarind polysaccharide gum, which is primarily prepared by heat-treating tamarind polysaccharide gum under an oxygen atmosphere at a temperature of 40 to 220°C and a holding time of 2 to 6 hours. The zinc mineral depressant is used for flotation of copper-zinc sulfide minerals. The present invention utilizes modified tamarind polysaccharide gum as a zinc mineral depressant, enabling efficient flotation separation of chalcopyrite and sphalerite. The depressant is biodegradable, environmentally friendly, has a wide range of raw material sources, is low in cost, and has a simple preparation method.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and in particular to a flotation separation method and application of zinc mineral inhibitors and copper-zinc sulfide minerals. Background Art

[0002] Copper and zinc are important nonferrous metal resources for the national economy and national defense, and are widely used in power transmission, communications, transportation, machinery manufacturing, and other fields. Copper-zinc sulfide ores are the primary source for extracting copper and zinc. With the development of society, the demand for copper and zinc continues to increase, posing challenges to the separation of copper-zinc sulfide ores.

[0003] Chalcopyrite, the most important copper sulfide mineral, often coexists with other sulfide minerals in the ore, such as sphalerite, pyrite, and galena. These minerals share similar physical and chemical properties, including density, magnetism, hydrophobicity, and electrical conductivity, making it difficult to extract a qualified copper concentrate product before smelting.

[0004] Froth flotation is the primary method for separating copper and zinc sulfide ores. Because chalcopyrite has superior floatability compared to sphalerite, copper-zinc separation is often achieved using a zinc-depressing flotation method. Even so, in actual industrial production, inhibitors are often added to selectively enhance the sphalerite's surface hydrophilicity, reducing its floatability. This, in turn, promotes the enrichment of chalcopyrite in the concentrate and improves the separation efficiency between the two.

[0005] Common inhibitors for sphalerite, including zinc sulfate, lime, and sulfite, are widely used in production practices. However, these inhibitors have issues such as high dosage, difficulty in degradation, and environmental pollution.

[0006] In addition, Chinese patent CN101693224A discloses a method for separating copper-zinc sulfide minerals. Water-soluble thioglycolate or thioglycolic acid, when used as a zinc mineral inhibitor, exhibits good selectivity, strong inhibitory ability, and easy addition. However, its preparation process is relatively complex and costly, increasing the cost of mineral processing operations and hindering the promotion and application of this agent.

[0007] Chinese patent CN109158214B discloses a flotation separation process for copper-zinc sulfide ores. The addition of zinc sulfate and sodium sulfite to the ore pulp acts as a combined inhibitor, which both increases the sphalerite's hydrophilicity and prevents adsorption of collectors on the sphalerite surface, thereby achieving copper-zinc separation. However, this agent is not easily degraded, and long-term, large-scale use can cause severe environmental pollution.

[0008] Therefore, there is an urgent need for an efficient, green and environmentally friendly zinc mineral depressant and copper-zinc flotation separation method.

[0009] In view of this, the present invention is proposed. Summary of the Invention

[0010] The first objective of the present invention is to provide a zinc mineral inhibitor using modified tamarind polysaccharide gum that can effectively separate chalcopyrite from sphalerite. Furthermore, the inhibitor exhibits high selectivity, requires minimal dosage, is biodegradable, and is environmentally friendly. The inhibitor also features low-cost raw materials and a simple preparation method. This approach addresses the issues of existing inhibitors, such as high dosage, difficulty in degradation, environmental pollution, and complex and costly preparation processes.

[0011] A second object of the present invention is to provide a flotation separation method for copper-zinc sulfide minerals, which uses modified tamarind polysaccharide gum as a zinc mineral inhibitor to flotate copper-zinc sulfide minerals, thereby achieving efficient separation of chalcopyrite and sphalerite. The modified tamarind polysaccharide gum has the advantages of strong selectivity, small dosage, easy acquisition of raw materials and low cost, which can significantly reduce reagent consumption, save mineral processing costs, and is biodegradable and environmentally friendly.

[0012] The third object of the present invention is to provide the use of copper concentrate and zinc-containing tailings obtained by the flotation separation method of copper-zinc sulfide minerals in the production of copper products and zinc products.

[0013] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are specially adopted.

[0014] The present invention first provides a zinc mineral inhibitor, comprising modified tamarind polysaccharide gum; wherein the modified tamarind polysaccharide gum is mainly prepared by heat-treating tamarind polysaccharide gum under an oxygen atmosphere; the heat treatment temperature is 40-220°C; the heat treatment holding time is 2-6 hours; the zinc mineral inhibitor is used for flotation of copper-zinc sulfide minerals.

[0015] Furthermore, when the copper-zinc sulfide ore is floated using the zinc mineral inhibitor, the dosage of the zinc mineral inhibitor is 80-300 g / t.

[0016] The present invention further provides a flotation separation method for copper-zinc sulfide minerals, comprising the following steps: grinding the copper-zinc sulfide minerals and mixing them with water to obtain a flotation pulp; adding the zinc mineral inhibitor to the flotation pulp, and adding a collector and a frother thereto to carry out flotation.

[0017] Furthermore, the grinding is performed to obtain a particle size of 75% to 90% by mass less than 0.074 mm.

[0018] Furthermore, the concentration of the flotation pulp is 27% to 35%.

[0019] Furthermore, the total usage of the zinc mineral inhibitor is 80-300 g / t.

[0020] Furthermore, the collector includes at least one of Z-200, ethylthiocyanate and butyl xanthate.

[0021] Furthermore, the total amount of the collector is 50-150 g / t.

[0022] Furthermore, the foaming agent includes at least one of terpineol and 2# oil.

[0023] Furthermore, the total amount of the foaming agent is 25-100 g / t.

[0024] Furthermore, the flotation includes roughing, scavenging, first cleaning and second cleaning.

[0025] The present invention also provides the use of the copper concentrate and zinc-containing tailings obtained by the flotation separation method of the copper-zinc sulfide minerals in the production of copper products and zinc products.

[0026] Compared with the prior art, the present invention has the following beneficial effects.

[0027] (1) The zinc mineral inhibitor provided by the present invention adopts modified tamarind polysaccharide gum, which can achieve effective separation of chalcopyrite and sphalerite, has a strong inhibitory effect, and is used in a small amount, which can significantly reduce the mineral processing cost. It is biodegradable, green and environmentally friendly, and has low raw material prices and a simple preparation method.

[0028] (2) The zinc mineral inhibitor provided by the present invention, on the one hand, the hydroxyl groups in the molecular structure of the modified tamarind polysaccharide gum can enhance the hydrophilicity of the sphalerite surface; on the other hand, the modified tamarind polysaccharide gum molecular structure contains a large number of aldehyde groups, which have strong reducing properties and will be hydrolyzed in the solution to obtain carboxyl groups, which can react with Cu in the pulp. 2+ Chelation of metal ions occurs to avoid Cu 2+ Activation of sphalerite; at the same time, carboxyl group is a strong solid-affinity group, which can be strongly adsorbed on the surface of sphalerite, significantly enhancing the hydrophilicity of sphalerite, thereby achieving efficient flotation separation between chalcopyrite and sphalerite.

[0029] (3) The zinc mineral inhibitor provided by the present invention uses modified tamarind polysaccharide gum as raw material, which has the advantages of wide source, low cost, biodegradability, and green environmental protection. In addition, the preparation method of modified tamarind polysaccharide gum is simple, the process is short, and it is suitable for mass production.

[0030] (4) The flotation separation method of copper-zinc sulfide minerals provided by the present invention adopts modified tamarind polysaccharide gum as a zinc mineral inhibitor to float copper-zinc sulfide minerals, which can achieve efficient separation of chalcopyrite and sphalerite, and has a strong inhibitory effect. In addition, the modified tamarind polysaccharide gum has the advantages of small dosage, easy acquisition of raw materials and low raw material cost, which can significantly reduce the consumption of reagents, save mineral processing costs, and is biodegradable and environmentally friendly. DETAILED DESCRIPTION

[0031] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0032] Unless otherwise specified, in the present invention, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor as implicitly indicating the importance or quantity of the technical features indicated. Furthermore, terms such as "first," "second," "third," and "fourth" serve only as non-exhaustive enumeration and description, and should not constitute closed-ended limitations on quantity.

[0033] Unless otherwise specified, the terms "include" and "comprising" used in the present invention may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0034] Unless otherwise specified, in the present invention, "one or more" or "at least one" refers to any one, any two, or any two or more of the listed items. Among them, "several" refers to any two or any two or more.

[0035] In a first aspect, the present invention provides a zinc mineral inhibitor comprising modified tamarind polysaccharide gum; wherein the modified tamarind polysaccharide gum is mainly prepared by heat-treating tamarind polysaccharide gum under an oxygen atmosphere.

[0036] The heat treatment temperature is 40-220°C, including but not limited to any one of 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 120°C, 130°C, 150°C, 160°C, 180°C, 200°C, and 220°C, or a range between any two of them.

[0037] The holding time of the heat treatment is 2 to 6 hours, including but not limited to any one of 2 hours, 3 hours, 4 hours, 5 hours, and 6 hours, or a range between any two of them.

[0038] The zinc mineral depressant is used to flotate copper-zinc sulfide minerals. That is, the zinc mineral depressant is used to flotate copper-zinc sulfide minerals.

[0039] The present invention uses modified tamarind polysaccharide gum as a zinc mineral inhibitor. On the one hand, the hydroxyl group (-OH) in its molecular structure can enhance the hydrophilicity of the sphalerite surface; on the other hand, the molecular structure contains a large number of aldehyde groups (-CHO). The aldehyde group has a strong reducing property and will hydrolyze to form a carboxyl group (-COOH) in the solution. The carboxyl group can react with the Cu in the pulp. 2+ Chelation of metal ions occurs to avoid Cu 2+ Activation of sphalerite; at the same time, carboxyl group is a strong solid-affinity group, which can be strongly adsorbed on the surface of sphalerite, significantly enhancing the hydrophilicity of sphalerite, thereby achieving efficient flotation separation between chalcopyrite and sphalerite, providing strong theoretical support for the flotation separation of copper-zinc sulfide ores.

[0040] After heat treatment and oxidation modification, the hydroxyl groups in the tamarind polysaccharide gum are partially converted into aldehyde groups, removing the bound water between the molecules and significantly reducing the molecular weight of the tamarind polysaccharide gum. With further reaction, some of the aldehyde groups in the tamarind polysaccharide gum are oxidized into carboxyl groups, breaking the molecular chain and further reducing the molecular weight. The oxidatively modified tamarind polysaccharide gum can selectively adsorb on the surface of sphalerite, hindering further adsorption of the collector on the sphalerite surface and increasing the hydrophilicity of the sphalerite surface, thereby achieving effective separation of chalcopyrite and sphalerite.

[0041] In addition, modified tamarind polysaccharide gum is a modified macromolecular agent of plant origin, which has the advantages of good selectivity, small dosage, strong inhibitory effect, wide source, low cost, and biodegradability.

[0042] Compared with traditional sphalerite inorganic inhibitors or combined inhibitors, the preparation method of the zinc mineral inhibitor proposed in the present invention is simple, and the raw materials are easily obtained, green and environmentally friendly, low in price, and can be naturally degraded.

[0043] The zinc mineral inhibitor provided by the present invention has good use effect, strong selectivity and small dosage. While effectively inhibiting sphalerite, it can significantly reduce reagent consumption and save mineral processing costs.

[0044] In some specific embodiments, the heat treatment may be performed using any heating equipment commonly used in the art, such as a tube furnace, but is not limited thereto.

[0045] In some specific embodiments, when the zinc mineral depressant is used to flotate the copper-zinc sulfide ore, the amount of the zinc mineral depressant is 80-300 g / t, including but not limited to any one of 80 g / t, 90 g / t, 100 g / t, 110 g / t, 120 g / t, 130 g / t, 140 g / t, 150 g / t, 160 g / t, 170 g / t, 180 g / t, 190 g / t, 200 g / t, 250 g / t, and 280 g / t, or a range therebetween. That is, the mass of the modified tamarind polysaccharide gum added per ton of the copper-zinc sulfide ore is 80-300 g.

[0046] The present invention uses modified tamarind polysaccharide gum as a zinc mineral inhibitor. On the one hand, the hydroxyl group (-OH) in its molecular structure can enhance the hydrophilicity of the sphalerite surface; on the other hand, the molecular structure contains a large number of aldehyde groups (-CHO). The aldehyde group has a strong reducing property and will hydrolyze to form a carboxyl group (-COOH) in the solution. The carboxyl group can react with the Cu in the pulp. 2+ Chelation of metal ions occurs to avoid Cu 2+ The carboxyl group is a strong solid-affinity group that strongly adsorbs on the sphalerite surface, significantly enhancing its hydrophilicity and enabling efficient flotation separation of chalcopyrite and sphalerite, providing strong theoretical support for the flotation separation of copper-zinc sulfide ores. Furthermore, the modified tamarind polysaccharide gum offers advantages such as good selectivity, low usage, strong inhibitory effects, a wide range of raw material sources, low cost, biodegradability, and environmental friendliness.

[0047] In some specific embodiments, the flotation method comprises froth flotation.

[0048] In a second aspect, the present invention provides a flotation separation method for copper-zinc sulfide minerals, including froth flotation. The method comprises the following steps: coarsely crushing and grinding the copper-zinc sulfide minerals, then mixing them with water to produce a flotation pulp. The zinc mineral inhibitor is added to the flotation pulp, and a collector and a frother are added thereto. Flotation is then performed to produce a copper concentrate and zinc-containing tailings. The zinc mineral inhibitor is modified tamarind polysaccharide gum, which is primarily prepared by heat-treating tamarind polysaccharide gum under an oxygen atmosphere at a temperature of 40-220°C and a holding time of 2-6 hours.

[0049] The flotation separation method for copper-zinc sulfide minerals provided by the present invention utilizes modified tamarind polysaccharide gum as a zinc mineral depressant to flotate the copper-zinc sulfide minerals, achieving efficient separation of chalcopyrite and sphalerite. Furthermore, the modified tamarind polysaccharide gum exhibits strong selectivity, requires minimal usage, and is readily available and low-cost raw materials, significantly reducing reagent consumption and beneficiation costs. It is also biodegradable and environmentally friendly.

[0050] In addition, the above flotation separation method has the advantages of simple operation, short process and high separation efficiency.

[0051] In some specific embodiments, in order to achieve effective monomer dissociation of the target mineral and the gangue mineral and improve the flotation separation efficiency, the ore is ground until the particle size of the mineral is less than 0.074 mm, accounting for 75% to 90% by mass, including but not limited to any one of 75%, 78%, 80%, 82%, 85%, 88%, and 90%, or a range between any two of them.

[0052] In some specific embodiments, due to differences in ore properties, flotation machine models and process flows, in order to achieve good flotation effects and avoid the adverse effects of too low or too high slurry concentration on the flotation process, the concentration of the flotation slurry is controlled to be 27% to 35%, for example, 28%, 29%, 30%, 32% or 33%.

[0053] In some specific embodiments, the total dosage of the zinc mineral inhibitor is 80-300 g / t, including but not limited to any one of 80 g / t, 90 g / t, 100 g / t, 110 g / t, 120 g / t, 130 g / t, 140 g / t, 150 g / t, 160 g / t, 170 g / t, 180 g / t, 190 g / t, 200 g / t, 230 g / t, 250 g / t, and 290 g / t, or any range therebetween. That is, the mass of the modified tamarind polysaccharide gum added per ton of copper-zinc sulfide mineral is 80-300 g. The total dosage refers to the sum of the dosages used in each stage of the flotation process (roughing, scavenging, and cleaning).

[0054] In some specific embodiments, the collector includes at least one of Z-200 (ethiocarbamate), ethiocyanate, and butyl xanthate. These collectors are effective in capturing copper minerals but have a weaker ability to capture other gangue minerals, facilitating the enrichment and separation of copper minerals.

[0055] In some specific embodiments, the total amount of the collector is 50-150 g / t, including but not limited to any one of 50 g / t, 60 g / t, 70 g / t, 80 g / t, 90 g / t, 100 g / t, 110 g / t, 120 g / t, 130 g / t, 140 g / t, and 150 g / t, or any range therebetween. That is, the mass of collector added per ton of copper-zinc sulfide ore is 50-150 g. The total amount refers to the sum of the amounts used in each stage of the flotation process (roughing, scavenging, and cleaning).

[0056] In some specific embodiments, the foaming agent includes at least one of terpineol and 2# oil.

[0057] In some specific embodiments, the total amount of the frother is 25-100 g / t, including but not limited to any one of 25 g / t, 30 g / t, 40 g / t, 50 g / t, 60 g / t, 70 g / t, 80 g / t, 90 g / t, and 100 g / t, or any range therebetween. That is, the mass of the frother added per ton of copper-zinc sulfide ore is 25-100 g. The total amount refers to the sum of the amounts used in each stage of the flotation process (roughing, scavenging, and cleaning).

[0058] In some specific embodiments, the flotation comprises roughing, scavenging, first cleaning and second cleaning.

[0059] In some specific embodiments, during the roughing process, the zinc mineral inhibitor, the collector and the foaming agent are added in sequence; during the scavenging process, the collector and the foaming agent are added; during the first concentrating process, the zinc mineral inhibitor is added; and during the second concentrating process, the zinc mineral inhibitor is added.

[0060] In some specific embodiments, the mass of the zinc mineral inhibitor added during the roughing is 3 to 4 times the mass of the zinc mineral inhibitor added during the first cleaning, and the mass of the zinc mineral inhibitor added during the roughing is 7 to 8 times the mass of the zinc mineral inhibitor added during the second cleaning.

[0061] In a third aspect, the present invention provides the use of the copper concentrate and zinc-containing tailings obtained by the flotation separation method of the copper-zinc sulfide minerals in the production of copper products and zinc products.

[0062] The flotation separation method for copper-zinc sulfide minerals provided by the present invention can achieve efficient separation of chalcopyrite and sphalerite, and uses modified tamarind polysaccharide gum as a zinc mineral inhibitor. The modified tamarind polysaccharide gum has the advantages of strong selectivity, small dosage, easy acquisition of raw materials and low cost, can significantly reduce reagent consumption, save mineral processing costs, is biodegradable, and is green and environmentally friendly, and has broad application prospects.

[0063] Among them, the copper concentrate obtained by the flotation separation method of copper-zinc sulfide minerals can be used to produce copper products, that is, copper-containing parts, components, products, etc.

[0064] Among them, the zinc-containing tailings obtained by the flotation separation method of copper-zinc sulfide minerals can be used to produce zinc products, namely zinc-containing parts, components, products, etc.

[0065] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all commercially available conventional products.

[0066] Example 1

[0067] The zinc mineral inhibitor provided in this embodiment is modified tamarind polysaccharide gum, and its preparation method is as follows: tamarind polysaccharide gum is placed in a tube furnace and heat-treated at 50° C. for 6 hours in an oxygen atmosphere.

[0068] Example 2

[0069] The zinc mineral inhibitor provided in this embodiment is modified tamarind polysaccharide gum, and its preparation method is as follows: tamarind polysaccharide gum is placed in a tube furnace and heat-treated at 100° C. for 4 hours in an oxygen atmosphere.

[0070] Example 3

[0071] The zinc mineral inhibitor provided in this embodiment is modified tamarind polysaccharide gum, and its preparation method is as follows: tamarind polysaccharide gum is placed in a tube furnace and heat-treated at 200° C. for 2 h in an oxygen atmosphere.

[0072] Example 4

[0073] This example provides an application of a zinc mineral inhibitor in the flotation of copper-zinc sulfide minerals. The zinc mineral inhibitor prepared in Example 1 is used to flotate copper-zinc sulfide minerals, and a pure mineral mixed flotation test is conducted. The specific steps are: 1 g of chalcopyrite with a particle size of 0.038 mm to 0.074 mm and 1 g of sphalerite with a particle size of 0.038 mm to 0.074 mm are weighed, mixed, and an appropriate amount of deionized water is added to the mixture and stirred evenly. The mixture is then poured into the flotation cell of a hanging trough flotation machine, and the flotation machine speed is adjusted to 1. The slurry was rotated at a speed of 690 r / min, the pH value of the slurry was adjusted to 7, 100 g / t of modified tamarind polysaccharide gum (i.e., 100 g of modified tamarind polysaccharide gum was added per ton of mineral) was added thereto and stirred for 3 min, followed by the addition of 100 g / t of butyl xanthate as a collector and 50 g / t of pine oil as a foaming agent (i.e., 100 g of collector and 50 g of foaming agent were added per ton of mineral) and stirred for 2 min, and aeration flotation was carried out. The obtained foam product and tailings were filtered, dried and weighed respectively. The yield and recovery results are shown in Table 1.

[0074] Table 1 Yield and recovery results

[0075]

[0076] Example 5

[0077] This example provides the use of a zinc mineral depressant in the flotation of copper-zinc sulfide minerals. The zinc mineral depressant prepared in Example 2 was used to flotate copper-zinc sulfide minerals, and a pure mineral mixed flotation test was conducted. The specific steps were as follows: 1 g of chalcopyrite with a particle size of 0.038 mm to 0.074 mm and 1 g of sphalerite with a particle size of 0.038 mm to 0.074 mm were weighed and mixed, and an appropriate amount of deionized water was added and stirred uniformly. The mixture was then poured into the flotation cell of a hanging trough flotation machine. The flotation machine speed was adjusted to 1690 r / min, and the slurry pH was adjusted to 8. 120 g / t of modified tamarind polysaccharide gum was added and stirred for 3 minutes. Subsequently, 100 g / t of butyl xanthate as a collector and 50 g / t of pine oil as a foaming agent were added and stirred for 2 minutes. Aeration flotation was then carried out, and the resulting foam product and tailings were filtered, dried, and weighed. The yield and recovery results are shown in Table 2.

[0078] Table 2 Yield and recovery results

[0079]

[0080] Example 6

[0081] This example provides the use of a zinc mineral depressant in the flotation of copper-zinc sulfide minerals. The zinc mineral depressant prepared in Example 3 was used to flotate copper-zinc sulfide minerals, and a pure mineral mixed flotation test was conducted. The specific steps were as follows: 1 g of chalcopyrite with a particle size of 0.038 mm to 0.074 mm and 1 g of sphalerite with a particle size of 0.038 mm to 0.074 mm were weighed and mixed, and an appropriate amount of deionized water was added and stirred uniformly. The mixture was then poured into the flotation cell of a hanging trough flotation machine. The flotation machine speed was adjusted to 1690 r / min, and the slurry pH was adjusted to 9. 140 g / t of modified tamarind polysaccharide gum was added and stirred for 3 minutes. Subsequently, 100 g / t of butyl xanthate as a collector and 50 g / t of pine oil as a foaming agent were added and stirred for 2 minutes. Aeration flotation was then carried out, and the resulting foam product and tailings were filtered, dried, and weighed. The yield and recovery results are shown in Table 3.

[0082] Table 3 Yield and recovery results

[0083]

[0084] Example 7

[0085] The flotation separation method for copper-zinc sulfide minerals provided in this embodiment uses a polymetallic sulfide ore from Inner Mongolia as an ore sample. The copper (element) grade of the raw ore sample is 0.44%, and the zinc (element) grade is 0.65%. The main components are chalcopyrite, sphalerite, pyrite, and pyrrhotite, as well as a small amount of bismuthinite and arsenopyrite. The modified tamarind polysaccharide gum prepared in Example 3 is used as a zinc mineral depressant. A one-coarse, two-fine, and one-sweep flotation closed-circuit process is adopted, comprising the following steps:

[0086] (1) The raw ore sample is placed in a ball mill and ground to obtain a grinding product with a grinding fineness of -0.074 mm accounting for 90% (i.e., 90% of the particle size is less than 0.074 mm in terms of mass percentage). The grinding product is transferred to a flotation tank and water is added to adjust the pulp concentration to 30%.

[0087] (2) Flotation was carried out using a single-tank flotation machine. 110 g / t of modified tamarind polysaccharide gum (i.e., 110 g of modified tamarind polysaccharide gum was added to each ton of raw ore), 80 g / t of collector Z-200, and 40 g / t of frother pine oil (i.e., 80 g of collector and 40 g of frother were added to each ton of raw ore) were added to the pulp in sequence. Each agent was added and allowed to act for 2 minutes before roughing was carried out. The roughing time was 5 minutes.

[0088] After that, scavenging is carried out, and 20g / t of collector Z-200 and 5g / t of foaming agent pine oil are added to the pulp (that is, 20g of collector and 5g of foaming agent are added to each ton of raw ore), stirred for 2min, and then floated for 5min.

[0089] Then, concentration I (i.e., the first concentration) is carried out, and 30 g / t of modified tamarind polysaccharide gum is added to the slurry (i.e., 30 g of modified tamarind polysaccharide gum is added to each ton of raw ore), stirred for 3 minutes, and then floated for 5 minutes.

[0090] Finally, concentration II (i.e., the second concentration) is carried out, and 15g / t of modified tamarind polysaccharide gum is added to the slurry (i.e., 15g of modified tamarind polysaccharide gum is added to each ton of raw ore), and flotation is carried out for 4 minutes to obtain copper concentrate and zinc-containing tailings.

[0091] The yield, grade and recovery results of this example are shown in Table 4.

[0092] Table 4 Yield, grade and recovery results

[0093]

[0094] Example 8

[0095] The flotation separation method of copper-zinc sulfide minerals provided in this embodiment uses a medium-sized porphyry copper mine in Sichuan as an ore sample. The main components are pyrrhotite, followed by chalcopyrite and sphalerite. The copper (element) and zinc (element) grades are 2.18% and 1.32%, respectively. The ore also contains small and trace amounts of chalcocite, hematite, limonite, calcite, quartz, etc. The modified tamarind polysaccharide gum prepared in Example 2 is used as a zinc mineral depressant. A closed-circuit flotation process of one coarse, two fine, and one scavenger is adopted, comprising the following steps:

[0096] (1) The raw ore sample is placed in a ball mill and ground to obtain a grinding product with a grinding fineness of -0.074 mm accounting for 85% (i.e., 85% of the particle size is less than 0.074 mm in terms of mass percentage). The grinding product is transferred to a flotation tank and water is added to adjust the pulp concentration to 30%.

[0097] (2) Flotation was carried out using a single-tank flotation machine. 150 g / t of modified tamarind polysaccharide gum, 120 g / t of collector butyl xanthate, and 40 g / t of foaming agent 2# oil were added to the pulp in sequence. Each agent was allowed to act for 2 minutes, and then roughing was carried out for 5 minutes.

[0098] After that, scavenging is carried out, 30g / t of collector butyl xanthate and 5g / t of foaming agent 2# oil are added to the pulp, stirred for 2 minutes and then floated for 5 minutes.

[0099] Then, concentration I (i.e., the first concentration) was carried out, and 40 g / t of modified tamarind polysaccharide gum was added to the pulp, stirred for 3 minutes, and then floated for 5 minutes.

[0100] Finally, concentration II (i.e., the second concentration) is carried out, 20g / t of modified tamarind polysaccharide gum is added to the pulp, and flotation is carried out for 4 minutes to obtain copper concentrate and zinc-containing tailings.

[0101] The yield, grade and recovery results of this example are shown in Table 5.

[0102] Table 5 Yield, grade and recovery results

[0103]

[0104] Example 9

[0105] The flotation separation method of copper-zinc sulfide minerals provided in this embodiment uses a polymetallic sulfide ore from Yunnan as an ore sample. The copper (element) and zinc (element) grades in the raw ore sample are 0.90% and 1.62%, respectively, and exist in the form of chalcopyrite and sphalerite, respectively. The gangue minerals mainly include quartz, pyrite, feldspar, and dolomite. The modified tamarind polysaccharide gum prepared in Example 1 is used as a zinc mineral inhibitor. A closed-circuit flotation process of one coarse, two fine, and one scavenger is adopted, comprising the following steps:

[0106] (1) The raw ore sample is placed in a ball mill and ground to obtain a grinding product with a grinding fineness of -0.074 mm accounting for 80% (i.e., 80% of the particle size is less than 0.074 mm in terms of mass percentage). The grinding product is transferred to a flotation tank and water is added to adjust the pulp concentration to 30%.

[0107] (2) Flotation was carried out using a single-tank flotation machine. 200 g / t of modified tamarind polysaccharide gum, 100 g / t of collector ethylthiocarbamate, and 40 g / t of foaming agent terpineol were added to the pulp in sequence. Each agent was allowed to react for 2 minutes before roughing for 5 minutes.

[0108] After that, scavenging is carried out, 25g / t of collector ethylthiocarb and 5g / t of foaming agent terpineol are added to the pulp, stirred for 2 minutes and then floated for 5 minutes.

[0109] Then, concentration I (i.e., the first concentration) was carried out, 50 g / t of modified tamarind polysaccharide gum was added to the pulp, stirred for 3 minutes, and then floated for 5 minutes.

[0110] Finally, concentration II (i.e., the second concentration) is carried out, 25g / t of modified tamarind polysaccharide gum is added to the pulp, and flotation is carried out for 4 minutes to obtain copper concentrate and zinc-containing tailings.

[0111] The yield, grade and recovery results of this example are shown in Table 6.

[0112] Table 6 Yield, grade and recovery results

[0113]

[0114] Example 10

[0115] The flotation separation method for copper-zinc sulfide minerals provided in this example is essentially the same as that in Example 7, except that 60 g / t of modified tamarind polysaccharide gum is added during the roughing process, 13 g / t of modified tamarind polysaccharide gum is added during the concentration I process, and 7 g / t of modified tamarind polysaccharide gum is added during the concentration II process, for a total amount of 80 g / t of modified tamarind polysaccharide gum. The yield, grade, and recovery results of this example are shown in Table 7 (the copper grade in the raw ore is subject to slight error).

[0116] Table 7 Yield, grade and recovery results

[0117]

[0118] Comparative Example 1

[0119] The flotation separation method for copper-zinc sulfide minerals provided in this comparative example is essentially the same as that in Example 7, except that zinc sulfate is used as the zinc mineral depressant, and modified tamarind polysaccharide gum is replaced with zinc sulfate during flotation. The amount of zinc sulfate used in the roughing separation is 1000 g / t, the amount used in the concentrating I separation is 300 g / t, and the amount used in the concentrating II separation is 150 g / t. The yield, grade, and recovery results for this comparative example are shown in Table 8.

[0120] Table 8 Yield, grade and recovery results

[0121]

[0122] Comparing Example 7 with Comparative Example 1, we can see that the copper concentrate obtained using the traditional zinc sulfate inhibitor has a copper grade of only 21.32% and a recovery rate of only 84.79%. Compared to Example 7 using modified tamarind polysaccharide gum, Comparative Example 1 exhibits a poorer zinc inhibition effect. Furthermore, the amount of zinc mineral inhibitor used in Comparative Example 1 is significantly higher than that in Example 7.

[0123] Comparative Example 2

[0124] The zinc mineral inhibitor provided in this comparative example is modified tamarind polysaccharide gum, and its preparation method is as follows: tamarind polysaccharide gum is placed in a tube furnace and heat-treated at 400° C. for 2 h in an oxygen atmosphere.

[0125] The flotation separation method for copper-zinc sulfide minerals provided in this comparative example is essentially the same as that in Example 7, except that the modified tamarind polysaccharide gum prepared above was used as a zinc mineral depressant for flotation. The yield, grade, and recovery results for this comparative example are shown in Table 9 (the copper grade in the original ore is subject to slight error).

[0126] Table 9 Yield, grade and recovery results

[0127]

[0128] By comparing Example 7 and Comparative Example 2, it can be seen that the copper grade and recovery rate of the copper concentrate obtained using the modified tamarind polysaccharide gum prepared in Comparative Example 2 are lower than those in Example 7, that is, the inhibitory effect of Comparative Example 2 on zinc is worse than that in Example 7. This is because the heat treatment temperature in Comparative Example 2 is relatively high, resulting in a large number of breaks in the molecular chains in the tamarind polysaccharide gum, carbonization of some polysaccharides in the molecules due to heat, and a significant reduction in the effective components that exert the inhibitory effect, thereby significantly weakening the inhibitory effect on sphalerite.

[0129] Comparative Example 3

[0130] The zinc mineral inhibitor provided in this comparative example is tamarind polysaccharide gum, which has not been subjected to heat treatment modification.

[0131] The flotation separation method for copper-zinc sulfide minerals provided in this comparative example is essentially the same as that in Example 7, except that the unmodified tamarind polysaccharide gum described above in this comparative example is used as a zinc mineral depressant for flotation. The yield, grade, and recovery results for this comparative example are shown in Table 10 (minor errors in the zinc grade of the raw ore are included).

[0132] Table 10 Yield, grade and recovery results

[0133]

[0134] By comparing Example 7 and Comparative Example 3, it can be seen that the copper grade and recovery rate in the copper concentrate obtained using the unmodified tamarind polysaccharide gum in Comparative Example 3 are significantly lower than those in Example 7, that is, the selective inhibition of zinc in Comparative Example 3 is significantly worse than that in Example 7. This is because the tamarind polysaccharide gum in Comparative Example 3 has not been oxidatively modified. Although the hydroxyl groups in the unmodified tamarind polysaccharide gum molecules can be adsorbed on the surface of sphalerite through acid-base interactions and hydrogen bonding, inhibiting the floatability of sphalerite, the selectivity of the hydroxyl groups is relatively poor, and they will also interact with the surface of chalcopyrite, inhibiting the flotation of chalcopyrite to a certain extent. At the same time, the unmodified tamarind polysaccharide gum has a large molecular weight and will act as a flocculant to a certain extent, causing fine particles of chalcopyrite and sphalerite to flocculate, exacerbating the difficulty of flotation separation of chalcopyrite and sphalerite.

[0135] In summary, conventional zinc mineral inhibitors, such as zinc sulfate, have poor inhibitory effects and require large amounts, resulting in severe environmental pollution. The modified tamarind polysaccharide gum provided by the present invention, however, exhibits a strong inhibitory effect as a zinc mineral inhibitor, enabling efficient flotation separation of chalcopyrite and sphalerite. Furthermore, the modified tamarind polysaccharide gum utilizes a low dosage, is low-cost, biodegradable, and environmentally friendly, meeting practical production needs. It can be widely used in the separation and flotation of copper-zinc sulfide ores.

[0136] Although the present invention has been illustrated and described using specific embodiments, it should be appreciated that the above embodiments are merely intended to illustrate the technical solutions of the present invention rather than to limit them. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents, without departing from the spirit and scope of the present invention. However, these modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A zinc mineral inhibitor, characterized in that including modified tamarind polysaccharide gum; The modified tamarind polysaccharide gum is mainly prepared by heat-treating tamarind polysaccharide gum under an oxygen atmosphere; The heat treatment temperature is 40-220°C; The holding time of the heat treatment is 2 to 6 hours; The zinc mineral depressant is used to flotation copper-zinc sulfide minerals; When the zinc mineral inhibitor is used to flot the copper-zinc sulfide ore, the dosage of the zinc mineral inhibitor is 80-300 g / t.

2. A flotation separation method for copper-zinc sulfide minerals, characterized in that: The steps include: After grinding, copper-zinc sulfide minerals are mixed with water to obtain flotation pulp; The zinc mineral depressant as claimed in claim 1 is added to the flotation pulp, and a collector and a frother are added thereto to carry out flotation.

3. The flotation separation method of copper-zinc sulfide minerals according to claim 2, characterized in that: The grinding is performed to obtain a particle size of less than 0.074 mm, which accounts for 75% to 90% by mass.

4. The flotation separation method of copper-zinc sulfide minerals according to claim 2, characterized in that: The concentration of the flotation pulp is 27% to 35%.

5. The flotation separation method of copper-zinc sulfide minerals according to claim 2, characterized in that: At least one of the following conditions is met: (1) The collector includes at least one of Z-200, ethylthiocyanate and butyl xanthate; (2) The total amount of the collector is 50-150 g / t.

6. The flotation separation method of copper-zinc sulfide minerals according to claim 2, characterized in that: At least one of the following conditions is met: (1) The foaming agent includes at least one of terpineol and 2# oil; (2) The total amount of the foaming agent is 25~100g / t.

7. The flotation separation method of copper-zinc sulfide minerals according to claim 2, characterized in that: The flotation includes roughing, scavenging, primary cleaning and secondary cleaning.

8. Use of the copper concentrate and zinc-containing tailings obtained by the flotation separation method for copper-zinc sulfide minerals according to any one of claims 2 to 7 in the production of copper products and zinc products.

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